1. Field
Exemplary embodiments of the invention relate to a vacuum insulation material. Particularly, exemplary embodiments relate to a vacuum insulation material having low thermal conductivity and in which a reduction of thermal conduction in an unfavorable direction effectively occurs during heat insulation thereof by pores in the heat-insulation direction.
2. Description of the Related Art
A vacuum insulation material is typically obtained by vacuum-packaging a core material or a gas adsorption agent in a gas barrier exterior material and suppresses thermal conduction by maintaining the inside thereof under vacuum. The vacuum insulation material has been used in an electrical product such as a freezer, a refrigerator, a warmer cabinet, a vending machine, a house wall material, or the like due to the low thermal conductivity thereof.
A glass fiber has been generally used as a core material in the conventional vacuum insulation material. The glass fiber may be scattered during the manufacture thereof or during manufacturing or dissembling of a vacuum insulation material including the glass fiber, and may adversely influence a human body, for example, through a worker's inhalation, skin irritation, or the like.
Accordingly, techniques using a thin plate-shaped cellulose structure as a core material of a vacuum insulation material have been developed in recent.